6-unit fixed bridge v. implant supported bridge

Last January I went to a dentist have my crowned tooth # 7 reattached, as it had broken off (at least 4 times in past 10 years). Unfortunately,  there was very little root left to attach a post. There was also significant bone loss for crowned teeth # 7, 8, 9 & 10. The dentist told be that they should all be pulled and be replaced with implants and new crowns after I had bone grafting performed.

As I am a 1 pack a day smoker I explained to the dentist that I would rather have a 6-unit fixed bridge rather than spend $20,000 + for implants that have an increased failure rate for smokers. He sent my impressions out for review and on my next appointment he told me that the span was too long for a bridge and that I really should have the implants installed or consider removable dentures. As I was only 45 yrs. old I decided to go with the 4 dental implants & 4 crowns.

I had the crowns/roots removed & bone grafting done in March 2008 and this past January had the surgical guide and molds made for preparation on the implants being installed. However 7 days before my implant surgery, my dentist called me into his office and casually stated that I did not have room for 4 implants so the plan is to now install 2 implants on a fixed bridge. He also stated that I needed to have both my canine teeth done (one is real,the other is a crown) in order to attach a temporary bridge while my implants are healing (since last March, I have had a flipper which has worked fine).

Needless to say, I am very upset with my dentist & oral surgeon, as it would see to me that it was very poor planning on their part in the very beginning of this whole thing. When I explained to the dentist that I had concerns about 2 implants supporting a bridge and one of the implants failing, making the bridge a complete failure, he told me I was wrong. When I told him that I was going to get a 2nd opinion from an prorthodontist he got extremely angry and down right verbally abusive.

I did consult with a prorthodontist and he stated that I could have three implants to support the bridge. However, at this point I just want a 6-unit bridge attached to my canines. I never would have agreed to have the three crowns pulled and bone grafting done had I bee informed that I could not have 4 implants and 4 crowns. Instead, I would have had bone grafting done for the crown that broke off and 1 implant & crown installed and dealt with the other three crowns when they became an issue (i.e. broke off, which could have been 1, 2 3 + years from that time).

Is it really a non-option for me to have a 6-unit bridge?

Thanks in advance.