Jay, Check out this thread.
http://www.srt10forum.com/forums/showthread.php?t=1431&highlight=kaholo . Lots of good info from 456 and Ed Snare.
I like my Snuglid SL very much. Many complements and bed stays dry here in rain country. Your price sounds is about right, I paid more (see the thread, but mine included installation and shipping to Hawaii).
Reference the solenoid lock, I have not added it as yet, (Ed Snare has it). After installing the wing, I found out that I could rock the standard key parallel in to the key slot with out much trouble.
$250 for the lock sounds a little bit high unless that includes installation. American Campers in Carson CA. Quoted me $170 plus shipping.
I have the factory under rail bed liner. My dealer only had to cut the lip on the front (over the rail by the cab) to install the lid. They did not cut the lip that extends over the top edge on the tailgate, since the Lid extends out over it and it is concealed. I like that since the top edge of the tailgate is what everyone hits when they load something into the bed.
I installed the spoiler my self. Biggest problem I had was to locating and drilling the mounting holes in the correct location. The point that the spoiler contacts the lid causes some distortion in marking the location to drill the holes. The base of the spoiler is flat, and the edge of the lid is starting to round off at the edge that overhangs the bed. I first made a paper template and laid it on the Lid. But wrapping the template around the corner of the lid effectively shortened the distance between the mounting holes on the passenger and driver side of the truck. I had covered lid mounting location with masking tape, so I screwed in cut off bolts in the lid, set the spoiler on the lid and marked to location where the bolts contacted the lid. If you have any more questions I am sure the folks on this forum will be glad to answer.
Also check
http://www.srt10forum.com/forums/showthread.php?t=368 (Jax Ram VCA Clone) for good pictures and discussion of mounting the spoiler to the SnugLid. Good luck.