My 12" RAS can do a 4" depth of cut, but as Roger points out, it's not practical for timbers, except perhaps some short pieces. Roger's exactly right: You can't get the timber flat against the fence to get a square cut. A heavy timber will distort the fence if you try - even if you build an extra heavy fence (don't ask me how I know this
) I use it extensivly for knee braces, however.
Makita has improved their 16" saw recently, for about the same money as you were talking about. You will want to upgrade to a carbide blade though. The new base is better than before, but still not as good as the after-market upgrade.
I've used a Makita 6" and own the HolzHer 8" planers. Although they operate a little differently (especially the technique needed for planing stock wider than the planer) they are both good machines. Keep the blades sharp! (Makita blades are resharpenable, the Holzher are not)
Oh - I forgot to mention compressed air, but ZAC picked that up. Always useful, if only for blowing things around. CB.