I have never had any problems with any of Performance's stuff. Forte is their brand of parts and accessories that they import directly. The only thing I would say about these shoes is that moutnain bike shoes are typically a lot heavier and thicker shoes than road shoes are. They will probably take a little bit longer to get into than tri-specific shoes would and your feet will be alot hotter. Performance always has good deals on their stuff (they seem to have a huge sale every week). I would suggest trying all the shoes on and see what you like about each type of shoe, there road specific shoes will probably be on sale next week so if there is something you like better than the mountain bike shoes, just keep you eyes open and they will be on sale soon.

Just keep in mind that SPD for a mountain bike and SPD-SL for a road bike are 2 different systems and are not compatible with one another. I started off like you, with SPD on both my MTB and road bike, but soon decided that the SPD shoe/pedal combo didn't work very well for me on the road bike. The SPD cleat has a very small point of contact with the pedal and your foot, and I was getting hot spots and numbness in my feet on 25+ mile rides. The switch to SPD-SL for my road and later my tri bike really helped. I suspect it's because the SPD-SL a wider platform with a bigger cleat and uses a stiffer road shoe.

If you really want MTB pedals & shoes for your current setup, I'd still say go for it. MTB shoes have the advantage of having tread on the sole, so you can walk in them a lot easier when necessary. Some beginners do use them in shorter tris, as they make getting around transition easier.

It's also never to early to start learning the art of clipping in and out of a pedal (and to get through the first few falls from failure to clip out!). While there are slight differences in clipping in with SPD and SPD-SL, the general concept is pretty much the same so once you learn on one system the other will be relatively painless.