I am a left handed hunter/shooter, and your dilemma rings true with me.
In 1989, when I decided to get away from the popular auto loading rifle of the time (Rem 7400), I purchased a Rem 700 LH in 7mm Rem Mag. Why that caliber? Because it was the ONLY left handed gun in the whole store (out of about 150 guns). I guess I got lucky, because I fell in love with the 7 mag caliber, and with a bell and carlson stock, bedding and free floating job, and adjusted trigger, It will shoot under any custom rifle makers accuracy guarantee in the country!
In 2002, after waiting and waiting for Remington to simply make their model 7 in left hand, I bit the bullet and had a custom rifle built on a 700 short action LH in 7-08 ackley improved. This gun is basically a model 7 in design as it wears a McMillan model seven stock and has a 20 inch barrel. I love this gun as well, but the problem is the price tag. It runs about $2250, without a scope.
In summary, the remington product is a good one and is time tested. That said, their attitude at the factory is TERRIBLE. I think they stand behind their product, but I hate to deal with them on the phone if you have any questions.
I hear that dekka, Ruger, and Savage are all good and they all offer left handed models. Something else to consider is the T/C Encore. In retrospect I have shot many whitetails and only three times have I ever made a second shot. In all three cases, the deer was hit the first time, the subsequent shot was a finishing one. As much as I like my custom gun, had I learned all about the ta/C Encore before hand, I may not have built the custom at that price tag.
As far as calibers go, if you are hunting primarily white tails, I would strongly suggest a short action caliber in a sporter/mountain rifle configuration with a 20 to 22 inch barrel. The versatility if this combo is super. The 7-08, 3-08 class of bullets will also work for the occasional elk/mule deer hunt.
If you are set on a .30-06 based caliber such as .270, .280, .25-06, .30-06, 35 Whelen, etc., then it would be hard for me to steer away from a Remington 700 BDL LH. There is just too much history and after market enhancments available for this gun that makes it a proven winner.
I've rambled on quite a bit here, but I understand your questions well. Good luck and feel free to PM me if you have any additional thoughts or questions.
Regards,
Smoky