Hi Mugnewbie
There are two different sizes of "standard mug" 10oz and 11oz
The 11oz mugs are heavier, chunkier and the general consensus is that they are not as nice or elegant as the 10oz
Most companies should state the capacity but I know that Xpres don't for some reason. However they are 10oz mugs just like the others sold all over. The best thing for you to do is firstly start with Xpres mugs because then everything is from one place. If you have any problems then you only need to refer to the one company.
Once you become more experienced you can then try BMS, Listawood, Longforte, Coralgraph even Ebay (if you dare!!!) and find the mug that suits you needs in terms of quality, price etc etc.
There is a huge range of standard mugs each with their own good points and bad points so it is really down to you as the user.
As I deal in bulk and am a cheap b'std I always go for the absolute cheapest I can find, you however may determine that your clients deserve the best mug on the market, which in my opinion right now is from BMS with all the others very close behind.
The same go's for latte mugs, in that most of them should fit most blankets
Lastly, ask as many questions as you want, this is what a forum is for. All I would say is try to do a search of the forum first as your question may have been answered (several times) before. Typing the same answer time after time gets a tad annoying
Good luck in your new venture and I hope you succeed.
SG
USING: Whatever it takes to get the job done...