At the risk of being accused of beating a dead horse, I would highly recommend one of the earlier Tamiya tanks.  Like Rob G. stated above, you can't go wrong with Hobby Lobby and that awesome 40% off coupon.  I use it every time I go to HL.  If you are still trying to refine your painting skills, I'd recommend an early Tamiya Pz. II or Pz. III or IV.  They are pretty simple kits, don't have the frustrating, at times, interlocking roadwheels found on the Panther and Tigers and have a low parts count.  On the American side, you can't go wrong with a Sherman or Lee/Grant.  Monogram once made some early Shermans with the initial suspension systems, but the tracks are horribly made.

Glad you're trying your hand at armor.  If you've done automobiles for such a long time, you shouldn't have too much problem with an armor kit.  Best of luck!!

GreySnake

The 1/35 T-34’s from Tamiya are good easy kits. They go together pretty fast with little fuss. They can be found easily for under $25. 

 

And they are possibly the most accessorized kits in Tamiya’s catalog - spare wheels, logs, tarps, boxes, snow cleats, all come in the box.  Loads of fun!

And their M113, although another older kit, has an engine and detailed crew compartment, plus crew and soldiers.

The 1/35 T-34’s from Tamiya are good easy kits. They go together pretty fast with little fuss. They can be found easily for under $25. 

stikpusher

Some of the older Tamiya 1/35 kits like their M41 or T-34 are perfect introductory projects for the novice armor builder.

 

I'll second the Tamiya M41 Walker Bulldog. Very easy kit and with the 40% off coupon at Hobby Lobby, it can be had for under $10 and looks like a stereotypical American tank when done.

Plus it is like a blank canvas and was used by many nations so you could go all out and make it unique.

1970s era model kit so there aren't a whole lot of parts.

If you want a more comprehensive kit, Hobby Lobby also has a nice 1/48 scale M1A2 Abrams and their new M4A3E8 Sherman in 1/35. Both kits are winners.

Yes a 1/35 Tamiya Sherman would be a great choice!

Thanks to all for your input, greatly appreciated 

I'd deffinetly echo what the guys said about Tamiya, can't go wrong there.

First you have to choose a scale.

The main ones are 1/72, 1/48 and 1/35. There are many different manufacturers and you should choose a tank that sparks your interest. At the start for your armour build experience, accuracy is not much the major draw but the experience that you gain. You already have skills which you can  bring over to the dark side.

Amusing Hobby have some nice armour kits which are easy to build and not expensive.

Trumpeter have a large range in all scales and they do build up to be nice display stuff, likewise Tamiya and the rest. Some manufactures are better than others, but for your first build choose a tank that you recognise or have some familiarity with.

There is plenty of help available. Just jump in and have some fun!

Well, as the guys already said (and who am I to argue?) the vintage Tamiya kits are really nice for something to learn on!!! Academy are pretty good too. 

Personally I'd avoid Dragon or AFV Club until I have some experience under my belt. Meng, Asuka/Takom, Hobbyboss, and Trumpeter are somewhere in the middle. 

Tamiya 1/35 kits are great for starters!

Some of the older Tamiya 1/35 kits like their M41 or T-34 are perfect introductory projects for the novice armor builder.

It's pretty hard to go wrong with the Tamiya kits. A lot of the older ones are pretty inexpensive. They go together quite easily and have a decent level of detail.

There are certainly more detailed and more expensive kits available, but the Tamiya kits are really a great place to start modeling armor.

Bill