Can't speculate on price for labor, but the front sack would work, watch out for sharp screws from the seat mounts near the bottom of each bow seat. It might not hold a ton of water but it would certainly help. it would involve four through hull 3/4" or 5/8" fittings, up by the rubrail. One drain and one vent per leg. You can get the cool chrome ones if you want. Plan on one fill, two drain pumps per bag, fill and drain Rule or Tsunami drain pumps. I like Rule 1100's and you can get them for 37.50 from Toyota on this site;)
Plan on 30 ft of sch 3/4 or 5/8 148 tubing (bilge rated) from ebay, 1-2$ a foot.
12 or 14 gauge wiring for the pumps, use marine red black pair from ebay.
5/8" makes the water shoot a long way, looks cool.
Switches, I used Mastercraft SPDT contura switches with labeled covers (ballast fill/drain), got them for 17 ea. Make a panel for them. See my posts for what mine look like.
You don't need to drill a hole in the bottom of the boat, use the forward bilge drain under the front of the engine as an inlet. You do not need a scupper fitting or anything, just screw a 1" bronze stub in there and commence plumbing.
