I do alot of highway too..Im at 2,500-2600 rpm's at 70-75 mph..Like I said, I love 4:10's w/ an auto and a centrify..I gained top end speed because of the 4:10's...
With the OEM 235/50-18(27.2")I turned 3000 RPM at 80 MPH. With the 295/45-18(28.3") I turn 3000 RPM at 85 MPH. I consider that streetable for an automatic
If you plan on running the car naturally asperated, no blower, or juice.. go with a 4.10 if you only drive 100 miles a week... from that it sounds more like city driving anyways... you wont notice a difference as far as gas goes cause after first it is just like with the regular gears... you just jump out of 1st a hell of a lot quicker.... if you do plan on going with juice, blower, or turbo go with a 3.73 it will give you a little bit to work with that way.... But it sounds like your staying N/A so go with the 4.10. as everyone says..... dont fear the gear
As far as who makes the gear.. it really doesnt matter... if they are installed correctly... and perfectly which i would hope a mechanic that does it every day can accomplish... you wont have road noise... and you wont have to worry which gear to go with... Motive makes a preformance one that rivals that of FRPP just fyi