Thanks very much for all your suggestions. Here is my current thinking on the front suspension for my '37 Buick. I have considered these suggestions during the last 6 months and this my current take on each.
XJ6 - I crossed this off my list because Jag XJ6 have very poor maintenance per Consumer Reports. I want to build this car once and do not want to build in maintenance issues.
Mustang II aftermarket kit (Probably Heidts) - I initially crossed this off my list because I had read of concerns on this and other websites. After talking to three individuals in person and numerous on-line who have had good success on cars similar to mine, this is now my current favorite option. I will have this installed by a local shop because I have not learned to weld yet and I see the set-up of the front suspension to be critical from a safety and function standpoint. I do have the large pockets on the side of the frame that will have to be removed.
I have also researched:
1937-1957 Buick Oldsmobile Pontiac upgrade wiki) - Greatest advantage is keeps more of frame unchanged. I found sources for the parts, but eliminated this as an option because it was too advanced for my skills and I could not find a local shop that would do it.
'75-'95 Truck Control Arms and Spindles - Rgreen wrote on hotrodders.com about this option. He used full size van upper arm, Astro van spindle, and modified the lower arm for a ball joint. I hoped to used all full size truck C1500 or van parts and a measured actual truck parts. Oldguy829 (who wrote 1937-1957 Buick Oldsmobile Pontiac upgrade wiki) helped me to explore this option by providing input and dimensions of older parts. Greatest advantage is keeps more of frame unchanged and common parts. I would also have to address power steering. It looks like this would be feasible, but it is beyond my skill level and would be difficult to find a shop.
Dodge Dakota Front Clip - Found others and a shop who have done this successfully. Adds rack & pinion and disc brakes. I eliminated it because Dakotas do not have good maintenance records per consumer reports.
Lexus SC400 & LS400 - These are reliable components with correct front track that look like good candidates. Need to build in the shock towers on the frame. A friend of mine is using front and rear from SC400 under a project. His friend put a front suspension under his 49 Ford truck and loves it. I do not have this skill at this point and believe the cost for this fab would outweigh the benefit.
Lincoln LS - Similar to Lexus notes above. The rear suspension is actually a jag (with good reliability) and I'm still considering it for there rear suspension.
'03-05 Crown Victoria/Grand Marquis - Great suspension and brakes. A friend of mine installed under a truck and this is one I could probably do myself. Too wide of track for my car. Found a shop in Utah who has narrowed the front suspension by 6.5 inches for install in '46 ford. Have not totally ruled it out, but have concerns about cutting and welding the alum cross member. Have not receive a cost yet. Check out horvathhotrods.com
One final note: I love cool cars, but I do not love to work on them. I have done all my own maintenance an all my cars (approx 40 cars to date) and my goal is to build a very dependable driver. Building a street rod out of my Grandparents car they bought in 1942 will be a huge learning experience for me that I will have to do a lot of the work due to cost.
Thanks again for all your feedback and let me know if I missed something.