Hi garybuss,
Your idea is perfect, and I have considered it myself (being a fellow reclining web-surfer).
There are many advantages:
1) You get to pick the exact components you want in the pc because you aren't tied to the laptop form-factor
2) If you need to get hardware repairs or upgrades done on the pc, anybody who knows how to work on one can do it because it isnt using proprietary laptop parts.
3) You can upgrade the entire system unit at any time without worrying that your investment in your LCD panel and other hardware peripherals is going to waste. After all, when you by a laptop you have to also buy the LCD, keyboard, and pointing device whether they are still good or not. They are built into the machine.
If you do this, consider buying an LCD with built in speakers. Many models of LCDs have them. That way your speakers will be right where you need them and will be an "elegant" solution by looking nice and not being off to the side somewhere.
Even though I am using a laptop, for a pointing device I use a trackball. Since the ball is "up" and not down like a mouse, it sits right on the arm of my recliner where I need it and works great.
Good luck,
LDB