Ah removals-how sweet. A few thoughts:
(note-some of what I say is to be applied to removals only.)
Barry, I wonder if you realize what you are getting into.
Forget the ascenders-you have the spikes, use them to get up the tree. If your in a position where you need to climb a rope (say suspended over a limb from a false crotch) footlock (after removing the spikes of course.) Forget about any "descender" too. What's wrong with a split tail and a blakes on your climbing line-very versatile.
You asked about ropes-every treeman I know has their own preference as to type and diameter-you have to find what you like and works for you. 120 feet is a common length around here although I know guys who do removals on 100 feet and I prefer 150 feet (rather have too much rope than not enough.) But speaking of ropes, if you do removals you're going to need rigging ropes, preferably more than one. Once again you need to find what you like. I tend to rig big so use 5/8" or 3/4" but I know guys who rope removals with 1/2". As to rigging ropes, in my opinion 150 feet is the bare minimum and 200 feet is my everyday length. Run a rope through a couple blocks, or as a speed line and it shortens up fast.
Who's going to be doing this roping, you or do you need a groundie?
A handsaw doesn't cut it on removals. At least two saws is handy-a small one to knock down the little stuff on the crown and a bigger one to work the stem.
You don't need to be a professional feller, but knowledge of at least the basics is essential in removals-sure the stem may only be 30 feet tall and you may have a rope in it, but you still need to know how to notch and backcut properly.
Brush and wood on removals can pile up quick! You'd be amazed how fast you can fill a chip truck on a big removal. How are you disposing of the brush and wood? It gets tiring cutting the wood up small and loading it onto the back of a pickup.
What about boots-have you stood on a pair of spikes for 10 hours straight?
Won't even touch on the little things that make life easier-blocks, false crotches, grcs, etc.
I'd advise you to work as a groundie for a while on a removal crew just to see what's really involved in laying a tree on the ground.
(note: the above opinions were just that-opinions. Not everyone will agree-take it with a grain of salt.)