Front focal plane is best. You don't need the biggest glass out there. Good glass, with good coatings, has such great light gathering ability it doesn't need huge bells.
I have three 3.5-10x LRT Leupolds. They are rock solid, made in Oregon by a great company that stands behind their product. I wouldn't consider anything else, personally.
US Optics products are sexy, but their admin folks were complete assholes when I was in the buying mood with cash falling out of my pockets.
I can't dispute that Carl Zeiss makes outstanding glass, but I didn't like the products they were marketing and the price point at the time I bought mine.
A 30mm tube with plenty of elevation is a good thing for long range shooting. Check out the snipercountry dot com for some good advice on optics. The site sells some stuff too! Great folks to do bidness with.