You'll be sorry if you put an "aggressive" cam in it, unless you're going to do a lot of racing. Most aftermarket cams are pretty dead on the low end, and develop there best power/torque at higher (than stock) RPM. With a "aggressive" cam you'll probably also experience driveability and idle issues. You'll then require an expensive aftermarket tune to correct these issues. Also, doing a cam without doing the complete package (intake, cam, valve train, tubular or SRT headers, and straight through cat. back) you won't realize the full potential of the cam. The cams were the last things I did to both my Hemi's after all of the above items were done. I also advanced the aftermarket cams in both my vehicles, in an effort to move the hp and torque curves to a lower RPM range. Worked great, but everyone recommended against doing it. I did my WK 2* and my LX 6*. The LX is much better overall, delivering a much better low end and 3-4 mpg better than with the stock cam. There is virtually no top end now though. The WK is not quite as strong on the low end, but powers pretty well all the way to ~6200-6300 RPM. It only gained a mile or two per gallon.
Best thing for you do to is check with some of the cam manufacturers to see what they offer. I went the the FRI Engineering Sidewinder cams, as they've been well proven in Hemi's for the last 7 years or so, and still retain the MDS if you desire. Parts (cam, valve springs, new valve seals, pushrods, SRT timing chain tensioner) should all cost less than $1000, plus installation, unless you do the install yourself.
06 GCO, Dk Khaki, QDII, Flshing Hi 3rd Bk Lt, MDS "ON" Lt, Airtab Vortex Gens, Debadged, Fumoto Drain Valve, BT Catch Can, Chopped EGR Tube, SRT8 CAI, K&N Filter, Sonnax Trans Line Press Booster, SC Tuner W/Adv Trans Tune App, DS Tuner, Cust tubular hdrs w/3 in Magnaflow/Xlerator AP Exh Sys, Bilsteins, SRT Springs/Sways, Cust Eng Cvr, SRT8 frt/rear bumpers, FRI Sidewinder Cam/6.1 valvetrain, SLP 25% UD Pulley, BBK true 90mm T-Body, SOS Ign Coils w/.060 spark plug gaps, SRT Reps with 265/45&295/40X20's.