I have a Pavilion DV7 for general use, but I'm sure it would be just fine for recording if I set up for it. I'd do a totally clean and fairly minimalist install of Win7 64 bit, stick Reaper 64 and a few decent plug-ins on there, stay off the Internet as much as possible with it and be pretty much good to go (after disabling any software services or hardware devices that weren't being used, of course). The lack of a Firewire port would be an issue for me as I don't know which USB interface would be the best option - maybe someone else could advise in that respect. I'd seriously consider upgrading the internal HDD to 7,200 RPM and maybe also using a small portable drive (quite probably USB 3.0) for recording to, especially if I was aiming to do a lot of simultaneous audio tracks or working with 24 bit/96 kHz rather than 16 bit/48 or 44.1 kHz (for examples). These upgrades can be done pretty cheap.
You should be able to run pretty much whatever software you want, IF you have the machine optimised for it. Be aware that getting any new machine straight out of the box and just sticking your music software on it is not likely to give you the best set up for recording, as I said. Will it be used just for your musical activities like recording and mixing? What sort of recording to you want to do? I'm guessing live bands either in rehearsal studios or on gigs as that's one of the obvious reasons for wanting a portable setup.