1) As far as the total cost, it's hard to say since he would be making the bars, but let's assume it's $175. The lights I have on their go for about $114 each, minus the wiring going up to them, relays, switches, etc. You can get away with running just two relays if you run 55 Watt bulbs in them. The relays will run you about $8 a piece, and the switch is a part # 96517, which will look almost factory. It will run you about $7 (you can use one switch for the whole thing). Not including the wiring, with the lights I used, you would be looking at about $770.
That being said, the lights I used are about as expensive as any Halogen light comes, and is top of the line. You can certainly use something less-expensive, such as the model 500 Driving Lamp, and they go for $45 each, which would drop the total down to about $424. You can also now find these lamps at Wal-Mart (the 500s), so you may be able to get them even cheaper, or check eBay. lots of people sell it on eBay.
Of course you can also go with fewer lamps, and if you simply do not like Hella lamps, you can use something else entirely.

2) I've been traveling quite a bit lately, so I have yet to complete the wiring, but I do have it in place.I just need to make the final connections. I ran a bundle of 4 14guage (I think) wires through a hole I drilled in the roof directly behind the plastic wind-deflector on the front of the rack.I damn-near poked a hole in the headliner when the bit popped through the roof, even though I started with a small bit and worked my way up. I did it on the Driver's Side, and then put the wires into some plastic loom to protect them from shorting on the sharp metal. I also siliconed the crap out of it after I fed them through.To date, we've had some pretty hard rain, and I have yet to see any signs of a leak. I fed this whole thing down the Driver's Side A-Pillar, under the dash, and through the large rubber grommet on the firewall on the Driver's Side. I just made a new hole in it, which you can do by taping the end of your wires to a long flat-head screwdriver, and just pushing it through a thin spot of the rubber from the inside of the cabin, then going to the other side, removing the tape, and pulling the screwdriver back out, leaving the wiring where you want it, with a nice tight seal around it in the grommet. I'll have my relays mounted on the Driver's Side inner-fender, with a larger, maybe 10-12 guage single wire going from the relays to the Pass. Side to the battery.The two wires for the switch can be small, since the relay needs only very little Amperage to operate, and it isn't carrying the load for the lamps themselves, and easily routed back through the same grommet, and I will have the switch located in the empty switch blanks in the center stack, but you can put the switch anywhere.

3) I haven't spoken to him about that lately. I know if he does it, he said he will want to take mine off and make a jig for it. I'll try and get with him this week or this weekend, and ask him more seriously.