I wouldn't do a package deal. Often times you can get better quality stuff for roughly the same price in the end if you piece it together yourself.
Do some research...
Alpine MRP-m500 amps are great for the price
I prefer Pioneer headunits...most people say avoid Sony like the plague. I've had one Sony. It was great...until it would randomly quit reading CDs a year later. It's now in one of my tractors at work...CD player blows nuts, but it at least picks up the country station I like. I replaced it with an older Pioneer headunit and have been using that for the past 5+ years with no problems.
Find someone who custom builds sub boxes for cheap on Ebay or using Google and buy the box you like...unless you just want a generic box. Then go with whatever...if you have specific subs in mind, try to match the volume of the box you pick out with the sub's volume recommendations. If you're good with wood (that sounds a little fr00ty...), you can build your own box for like $30 out of 3/4" MDF. Just need a sheet of MDF, some screws, liquid nails, and a good set of speaker terminals. If you run around with the top off a lot, coat it with bedliner rather than carpet it to waterproof the wood.
Subs - I have Elemental Designs subs that I love, but everyone has their opinions on subs. Kicker makes some good entry level subs, but I really can't recommend specific sizes, models, etc as I'm not familiar with anything but the eD stuff I've run in the past.
Wiring - I use KnuKonceptz (Amp Installation Kits, HDMI Cables
) for all my sub builds. Prices are cheap, quality is much better than that Walmart crap.