In West Central Texas, the deer tend to be a bit on the small side. This year, I took a large one that field dressed about 130 lbs. My suggestions are based on my field experience, i.e. I tend to recommend what I use.
As to rifle: If your friend is a one gun guy with a $1000 budget he has a number of options, but my choice would be a Tikka T3. There are a number of other good options mentioned above. One that is usually overlooked in this forum is a T/C Venture. It is in the same accuracy class as the Tikka in my experience. However, I like the Tikka safety a bit more. A plus of the Venture is that the Weaver (Picatinney) bases are hard mounted on the receiver out of the box. Just add some Warne rings and a scope and you are good to go. Scoping the Tikka is a bit more exciting. The Ruger M77s are nice, classic bolt guns, but to not tend to be as accurate as the Tikka or T/C without some tender loving care. Also, I have had some trouble with the Ruger scope mounts on a couple of M77 and a No.1 RSI.
Optics would be a Bushnell Elite 3500 (Natchez has a 4-12 x 40 very attractively priced right now). I hunt with a Bushnell Elite. About the best scope I have found for Texas hunting is a Leupold VX-3i 2.5-8x36. They are bit pricey, but have the best lower light performance (sunrise and sunset =/- 30 minutes) of any scope I have used in West Texas field conditions. The Bushnell Elite 3200 (now superceded by the 3500) 3-9x40's are nearly as good as the Leupold 2.5-8 and cost $150 less. Redfield scopes should also be considered. Personally, I dislike scopes with large turrets. I don't have time to dink with them while hunting, they tend to get hung up on brush or dig into your back or hit against the pickup door jam (Murphy rules), and you put yourself in the position of accidentally knocking the scope off zero.
Cartridge: So far (in over 50 years of hunting West Texas) I have taken deer with 243 Win, 6 mm Rem (over 30 feeding myself and roommates in college and then myself after--our ranch is in a 5 deer county), 6.5 Creedmoor, 270 Win, 7-08, 30-40 Krag, 308 Win, 30-06 (10 or so), and 300 Weatherby Magnum. All of these deer were equally dead. Of the choices available, I think that the 6.5 CM is probably best balanced of these. The trajectory of the 129 gr SST Hornady Superformance 6.5 CM is virtually identical to the 117 gr Hornady American Whitetail loading out to 300 yards--then the 6.5 starts to be a bit flatter. It also has relatively low recoil. However, bullets from all the other cartridges will not bounce off deer as has been implied by other advocates of this cartridge. Also, I just happen to like short action cartridges.
Above all, the rifle has to fit the shooter. Not all rifles will fit all shooters, and what works for one marksman may not work for another. Your friend should go to a good gun store and shoulder guns till he finds something that fits and gives him confidence. There are a lot of good choices (e.g. Howa/Weatherby and Sauer) that have not been mentioned. I have found that some guns will "speak" to me when I handle them. Often they tend to follow me home. Confidence in the gun tends to help the hunter be successful.