Icom IC-706 MkIIG has been out of production for about 14 years. If you are looking to buy one, understand that it is not a new radio. Also understand that due to the compact nature of the IC-706 and IC-7000, these radios are prone to heat-related failures.
Yaesu FT-897D has been out production for about 9 years. The FT-897, FT-857, and FT-817 are all basically the same radio in different boxes though the 897 and 857 have different final amplifiers. Again, lots of electronics crammed into a small space.
A problem that is gradually becoming worse and worse is that older electronics devices are nearly impossible to service. If specialized ICs were used in the original design, such as DSPs, FPGAs, CPUs, they may no longer be available from the chip manufacturers and few repair shops can do board level repairs anyway. If the shop can't get a replacement main board or logic board or PA board from the manufacturer or a "parts radio", you're screwed.
Since the two radios you list have basically the same band coverage, I'll jump to the conclusion that you are looking for a "shack in a box" solution. I generally recommend against these sorts of radios. For one, in most parts of the country, FM is the predominant mode on 2m and 70cm so paying for CW and SSB modes on those bands may be a waste of money. The second reason is that if one part of the radio fails, you are entirely off the air while the radio goes in for service. I think you might be better served by getting a good HF+6m radio, like an Icom IC-7300 or a used Kenwood TS-590SG, and a good VHF/UHF dual-band FM mobile radio.