Below are some of the vehicles I have. The Panther on the left is a Corgi 1:50 pre-cast. Really nice model crying out for a proper paint job (and the turret and tracks turn too) The Sherman in the centre is a Westwind 1:60, the unmade Panzer IV is S and S models, they say 1:56 scale but I think maybe a little towards the 1:60th, and the Stug on the right is a BTD lead monster at 1:50th. As you can see relative to the WW Sherman the other two (Corgi and BTD) are considerably bigger.
Personally for gaming I prefer the slightly smaller vehicles, as this moves it awy from the the GW superscale of things and allows for a game that feels a bit more in scale. The 1:50th models look a little more right next to the infantry (although remeber that the bases they are on raise them up a bit too) but either way either scale looks well I think.
BAM's models (I have only seen a Tiger 1E 'in the flesh') looks about right at 1:56 (and that's what they are advertised as on the website) their detailing and support from the company looks spot on, although I have no direct experience of this.
The Westwind Sherman is nicely cast, and around £18 I think, the Panther was £10 in a sale, the Stug was the £16.76 or whatever BTD charge. I added the shurzen side skirts myself and is a nice model, but physically heavy and took a lot of work to get there. The S and S models are nice, although the detail isn't that sharp. Shaun at S&S did me a good deal with his existing stock so maybe worth a ring if you're not to bothered about having top notch quality.
Overall I'd go for either BAM, or my personal favourtie Westwind, if you go for BAM, then make sure you get vehicles without the cast base, they look naff!