Greeting's;
Not sure on what to vote?
I have set out information regarding the suggested tanks and some basic specs, the Vickers MBT will be explained together.
Centurion Mk 7/1
Development
This upgraded version of the Centurion was developed by Leyland Motors and featured an expanded hull, improved cabin design, larger fuel tanks, and enhanced armour.
The Centurion Mk. 7/1 was the ancestor of the MBTs (main battle tanks). It takes the features of the Mk. I, adopts them and improves upon them greatly.
Specification's
Gun : 105 mm Royal Ordnance L7A1
Turret : Centurion Mk. 7
Engine : Rolls-Royce Griffon 950hp
Suspension : Centurion Mk. 7
Radio : SR C42
Historical Information
In 1943, the Directorate of Tank Design was asked to produce a new design for a heavy cruiser tank under the General Staff designation A41. After a series of fairly marginal designs in the A series in the past, and bearing in mind the threat posed by the German 88 mm gun, the War Office demanded a major revision of the design requirements, specifically: increased durability and reliability, and the ability to withstand a direct hit from the German 88 mm gun within a maximum weight of 40 tons. The hull was to offer more protection against mines and top speed was not vital while agility was to be equal to that of Comet. A high reverse speed was also required.
Vickers MBT's
Vickers MBT Mk1 Development The Vickers MBT followed on from a 24-tonne 20-pdr gunned tank design intended for export. This would be as well equipped as Centurion but substantially cheaper and with Vickers Vigilant missiles as effective. However with the appearance of the 105 mm L7 gun into the British, US and German tank designs, this light tank would have been less powerful while too large for the reconnaissance role, and so a new design was required. With armour twice that of the light tank design, it would still be 12 tonnes lighter than Centurion and hence more mobile. The design would use the new engine and transmission of the Chieftain tank then being developed. The development coincided with an agreement with India in 1961 to produce a tank design and help set up a factory there to produce it. Vickers MBT Mk7 There's not enough information on this tank from its short appearance to the battlefield.
M60A2 Starship
Development The M60A2 is a variant of the M60 main battle tank and was developed as a force multiplier for units, operating the M60A1 MBTs. Its development began in the late 1960s. This vehicle entered service with the US Army in 1972. A total of 526 M60A2 main battle tanks were built. This vehicle was nicknamed Starship due to its sophisticated technology. However the M60A2 was not a successful tank. It was withdrawn from the US Army. Basic Information The M60A2 was completed with a new turret, housing the M162 152 mm gun/launcher. A similar gun was previously used on an M551 Sheridan light tank. This gun could fire both ordinary munitions and MGM-51 Shillelagh anti-tank guided missiles. The ordinary munitions were short, fat, with combustible cases and had to be carefully handled. These rounds had a range of effective fire of 1.5 km and were sufficient for infantry support role, but had poor accuracy on longer ranges. The Shillelagh anti-tank guided missiles were intended to deal with hostile tanks at longer ranges. Missiles were stored in aluminium cases and had a range of up to 3 km. Apparently operational experience of this unusual tank revealed that the 152 mm gun was inferior in terms of range and accuracy to 105 mm and 120 mm tank guns, firing ordinary munitions. Furthermore the Shillelagh anti-tank missiles could not penetrate armour of the emerging heavily protected Soviet MBTs, such as the T-80. The tank and Shillelagh missiles had complicated electronics and guidance systems. These were expensive to produce and troublesome to maintain. These missiles ended up almost never being fired, except for crew training purposes. Initially there were a number of problems with the new gun, but eventually most of them were solved. 
Some Basic tank suggestions that you can discuss about in the comment's but focus on the 4 tanks suggested above.
T-55
Chieftain Mk4 (Challenger Prototype)
This tank was really well armoured for the time period.
Ru-251 (A.K.A the mini leopard)
Best Regard's; 
Magic Ender11
TECREAT - Tanktastic English Community REcreational and promotionAl Team
