What to get next for the avy

Hey guys im a newbie here, driving a 2002 Avalanche North Face edition,   i have flowmaster 1 into 2 exhaust,  today i did the MAF cleaning  and seafoam got a lot of my lost power, she now flies down the highway,   anyways i was getting 17mpg highway before lets see hyow i do now,,,
My question is what should i do next performance wise and penny wise (pockets not too deep lol)..   should i go air intake or work in the tuning to get rid of the slight bog it still has on take off,,

If intake i was looking at spectrum and K&N  spectrum is almost $100 cheaper, is the k&N that much better to make it worth me spending the extra 100

Intake for sure.

Post is almost two years old, I guess he has done something since then.
Just my .02 but in my experience the performance/mpg alleged increase is not worth the money for a CAI.
If I wanted big performance I would have bought a Corvette and for mpg I would ride a motorcycle.
The AV is not a good starting point for a performance vehicle due to it poor aerodynamics and it's weight. If I wanted to increase power in an AV I would save for a Magnacharger supercharger.