I would personally work from the middle in either direction, nearly always purchasing the best component you can manage. The exception I would make is the preamp. If possible, skip the preamp until the last piece is in place, but prior to getting carried away with cabling (that is if you do get carried away). Prior to cabling I would also purchase a really good rack like the Mapleshade Samson. If you can justify it, buy the rack before anything else. This way you will have a good reference point when auditioning equipment purchases.
Only after these things are covered would I recommend "voicing" your system with cabling or power cords. The rack and any isolation solutions should be in place before this "voicing" is commenced. I have personally found greater impact from power cords and speaker cables. Others have had a different experience.
If you are set on the speakers, I would ask the speaker manufacturer for his amp recommendation for that particular model. If you purchase an amp prior to your speaker purchase, make sure it is compatible with the speaker you expect to purchase in the end as well as being sufficient for the interim.
Set your sights high and try to make only one purchase per component. Patience is a virtue they say.
BTW, I agree with me too. ;-)