I've been using a similar build, since I had the XL 260 left over from my JM6-DD. Any 'Mech that can use spare parts gets points for economy in my book. Swapped out the streak in the narc launcher for a standard SRM4, and replaced the small pulse lasers with mediums for range. If I had an XL 255 for it, it'd be a very tough and versatile little bird. Streaks config is probably a better light hunter, but I'd still drop the small pulsers for mediums. Rok
Lately I've been running a similar build, but with a max engine. Drop the SPL down to regular small lasers, and drop the armor to 197 points, and you can fit in an XL295. I really love being able to snipe with an ERLL, and still have some teeth for a knife fight.
I think Sir Tiddles already did a very good job of slightly reworking this build. I'd put both SLas in the RA while keeping the ERLas in the torso, as you don't need the arm pitch as much when sniping. It'll also improve the convergence of the SLas quite a bit, as I don't think you're using 2 separate weapon groups for them, are you? Oh, and never ever lower your light mech's armor when there are better parts to do so. I actually do like this one quite a bit. This might become a new favorite of mine.