Good point, I'd say stick with your epic for the instrument modifiers. As far as some easy upgrades.
Look to get some Dweium Trio Jewelry with the following Augs put in (pardon my spelling):
1) Round cut Perdiot
2) Round cut Opal
3) Square cut Taafite
If you get these for your bracers, rings, earrings, necklace, and face piece you're looking at a substantial increase in your AC/HP/Mana. Just those pieces alone will get you somewhere around 3200HPs and 280AC. I don't know what they are going for these days, as I have had friends make them for me, however, I think the price is dropping. That should get you started. These are better pieces (in my opinion) than going for the elaborate cultural armor w/ Exaulted Augs for bracers, etc.
If you are talking more higher end (read: expensive items), you can pick up warped steel armor for an average of 200k a piece or so.