Pascal, the one you're looking at: http://www.mlcswoodworking.com/shops.../tabletop.html
seems serviceable enough, and would get you started quickly. It's similar to units available at Rockler and various other sources.
I agree that the larger table surface is probably better, if you have space for it.
FWIW, when I bought mine (a Rockler top on sale for a bit less than the MLCS), there were several factors I considered:
1. thickness of table (you want it to be very stable, so it won't sag at all under the weight of the router),
2. size and material of the plate to which the router is attached (the more rigid the better, especially with large, heavy routers),
3. the size and design of the fence,
4. the size of the maximum bit opening. (important for raised-panel bits, and such)
I considered building my own top, but the cost of the plates alone was a key factor. In general, they all seem way over-priced for what they are when purchased separately. I would have preferred a 3/8" aluminum plate, but settled on the 1/4" aluminum plate included with the Rockler top I bought.
Another factor to consider is whether the plate is pre-drilled for the router you intend to use. While you can drill it yourself, exact centering and hole placement can be tricky.