i would be careful with coilover suspensions. i have done some extensive reading, and while they ARE popular, they can create some problems. the macpherson strut system in our beloved mustangs relies on two strut "towers" at the front of the car. These towers (where your struts mount) were not meant to support the entire weight of the car, which they will be doing under a coilover setup. This can create loads of chassis flex, and even misalignment, under hard cornering or heavy driving, ESPECIALLY with a heavier 351.
The coil springs perch into the k-member, distributing weight between the struts and coil springs, and between the strut towers and k-member.
The tubular k-member, however, is a great upgrade for correcting steering geometry issues, and saving weight.
for coil springs, shocks, and struts, i would recommend the bullitt equipment from ford. It is for the newer 94-04 stangs, but fits ours just fine (aside from the sway bars). you can find it at ppi (performancepartsinc.com) or summitt. at summit, search for 94-04 suspension packages. it comes with the sway bars. at ppi, you can buy the components seperately. its a great setup, and is pretty cheap.
__________________ 1965 Mustang Coupe Project: 1965 Mustang Inline 6 (For Now) Coupe, New Floors, New Quarters | Ford 9 Inch Rear, 11" Rear Disc Brakes, 3.50:1 Gears | Control Freak Front U/L Control Arms, Global West Adj. Strut Rods | KYB Gas-A-Justs, Grab-A-Trak 620 Coils & Mid-Eye 5-Leafs | Global West Tubular Subframe Connectors | Addco 1-1/8 Front Swaybar Kit |