I have a question, would an option for lack of spellcasting be solved with Leadership and a cohort being the support caster?
I think totally. I'd imagine a 17th level caster or artificer will do better casting than your character can. It might not be necessary, but they could dip into Spellguard of Silverymoon to cast personal spells on you.
It also depends a bit on what sort of epic environment you're operating in. The Epic Level rules are somewhat hopelessly out of date and problematic -- Epic Spellcasting being the most notorious offender, but there are others (e.g., the Dire Charge feat being superceded and then some by Lion Totem Barb).
I have played a fair number of epic games w/ fairly high-powered characters and w/ a group that is firmly in the "practical optimization w/ gentleman's rules" spirit. In those games, fighting mostly epic monsters right out of the book or modified w/ templates (e.g., fought an intelligent version of the Tarrasque w/ a few templates on him), non-spellcaster characters did quite well. Hell, a straight-up Paladin, w/ a quick dip into Marshal and the right feats did really well, and the most powerful (or, at least, the most frustrating to the DM) was my Rogue who had some Spellthief-type abilities.
That's been my experience, at least, but it may be worth scoping around to see what else is on the board and asking your DM how much he wants to push the initiative war or ask you to shoot for "real ultimate powah!" Personally, one of the things I find nice about higher level games, one of which I'm about to run whenever my players get their collective acts together, is that you
don't have to optimize much to have something awesome and interesting.