I don't think the Stiletto is the head you are looking for. I brought it home and spent a couple of days with it. It's not a super high gain head, but neither are (most of) the tones you mention. It is suited well for AC/DC grind and you can get a pretty close Brown Sound EVH tone also. Led Zep is in there too. I thought the amp was simply too piercing. I've played Marshalls and know the difference between el34s and 6l6s, unlike alot of those who have wrote this head off. But really, this thing will bite your forehead off! I'm sure that you could tone it down a bit with different tubes/speakers/eq et al but that was my end opinion.
For the Clapton and Hendrix, I think you want a more traditional Super lead head, maybe a RI or a clone (www.metroamps.com, www.voodooamps.com) with an attenuator and a fuzz for the Jimi and a Tube Driver for the EJ violin tones. The Vai stuff is a different beast altogether from the others you mentioned but I'm sure you could achieve something close with some sort of screamer type OD that bumps your mids.
You also might want to look at substituting el34s for the 6l6s in your Lonestar, since most of the tones you mention are el34 based (well, early Clapton anyway).
I plan on picking some up today and if you like I'll post my thoughts later after I spend some time with them. I actually might make clips of the two if I get ambitious...
Yeah man that will be cool, I would love to hear how the Lonestar sounds with EL34'S