Hi there Mike,
Seriously, putting two S-es in your Strat will not harm your current tone in any way. I'm even a bit flabbergasted that anyone would come up with the idea of mounting a single humbucker in a guitar that could be so versatile
(I don't know the names of the band members but is there a Mike in Blink 182? :icon_tongue
That's my point. Some point, anyway.
The first guitar I bought was a MIM Superstrat (Superstrat means S-S-H, just to make sure we're on the same page here
) I smashed it during band practice and while playing some lousy gigs (Yeah I was wild back in '01) but it was one of the best guitars I've played, and during time, I've played quite a few.
Adding two S'-es will not alter the bridge humbucker tone, assuming you put in a proper 5 way switch and two tone pots. On a strat, traditionally the bridge pickup is only wired to the master volume pot; the two tone pots are only influencing your middle and neck sounds. Because of that, when you put the 5-way switch in position #1 you will get exactly the same sound you're getting now!
Of course, If you decide to put these 2 S-es in, you have a lot of options as to brands and models. I must say I am not at all to experienced with that, but I put in a set of Kinman's in my Telecaster the day before yesterday and they sure live up to what is being said on the Kinman website. My Telecaster now has absolutely no hum - as in: less hum than my humbucker-equipped Ibanez and other humbucking guitars i've played - and they have got fantastic tone! (These Kinman's ofcourse are just a suggestion so that you might check them out, I am in no way affiliated with Kinman :icon_tongue:
I hope to have been of some assistance.