I have never dealt with The Wet Spot, but all I have heard about them is very positive.
To the corys question. Yes, these two will be fine together with sufficient numbers. You never have to worry about corys not getting along. The very large species, which are now in the genus Scleromystax, can be a bit rough at times, but the species still in Corydoras are very docile with each other and any other fish. However, numbers are extremely important.
Corydoras trilineatus should be in a group of five or six minimum, but if this is the only species I would get a few more. You don't mention tank size as others have noticed, but a group of these is mandatory and will be better whatever the tank size so provided it is sufficient for corys, you're fine. BTW, C. trilineatus is almost always the actual species offered in most stores as C. julii, which itself is very rarely seen.
Corydoras habrosus is a bit different, being one of the so-called "dwarf" species. Higher numbers are much better, no less than 10-12. And while all corys are better with a smooth sand substrate, this species needs it or it usually will slowly deteriorate. Temperature is also more important, and should not exceed the mid-70's F.
Byron.