+1 on ajc's comments & the other comments above.
I can maybe put things into some perspective for you. My first build was a Trinity 18. I'd have to say that was pretty much a learning platform for me. I'm sure Stephen will agree I had a lot of questions about the tone when I first built the thing (many of them probably somewhat stupid I'm sure!

). I've recently rebuilt it (and converted it to the sIIIV6 layout).
My next build was a 2204 clone using Ceri@tone's chassis, panels & board. I sourced all the parts rather than going a pure kit route on that one (I wanted a true custom build...or as close as I could get with my limited skills/resources). Compared to the Trinity 18w, I'd say it was about on par difficulty wise.
I've built 4 or 5 amps since the 2204, the most recent being the Triwatt. In some ways the Triwatt is actually an easier build. The board, for example, is easier to work on due to it's "rectalinear" layout even though the component count is higher. The side effect is there's a lot of jumpers that can easily get missed (as you will see in the early Triwatt build threads, mine included). Also, with the top-mounted iron there's more working room in the chassis. If you have big clumsy fingers that's a wonderful thing!
In other ways, the Triwatt is the most advanced build I've done so far. There's a lot going on under the hood of this puppy. Attention to detail is key. Stuff like lead dress & routing are CRITICAL to a quiet, well functioning amp. The higher component count also means there's a lot more spots for things to go wrong, and that can make debugging more of a challenge. I would call this a more advanced build for sure, and probably not a good choice for getting your feet wet.
I'm not trying to deter you by any stretch! I say go for it if it's what you want, but take your time. Triple (or quadruple) check everything. Read through all the build threads posted so far. Have a close look at Zaphod's build pics for pointers on laying out the wiring for a quiet & well-behaved amp. Read the builder's guide thoroughly - there's a ton of great info in there, and it really helps to understand what you're actually creating.
And if you have a question, ask! I can guarantee you'll get top notch support from Trinity & many of the folks on these boards. If you have issues, we've been there in most cases and we're all happy to help. In the end you'll have a Killer amp.