24vAC to Multiple DC Supplies
If you have 24Vac then after rectification and smoothing this will be more like 32Vdc or maybe 33Vdc. The first thing you need to do is reduce that to 24Vdc for powering the relays and op-amps. I'd use a switcher because using a linear (at 700mA) is going to dissipate 6.3 watts.

In fact I'd use switchers for all the rails (all powered from the raw 32Vdc voltage). 

If the 24V dc rail needs to be fairly "quiet" for the op-amps I might consider using a switcher to generate 25Vdc then a LDO linear regulator to take 25Vdc to 24Vdc (this would dissipate about 1 watt in total). 

Alternatively, if the op-amps were only using 50mA (guesswork) I'd generate two 24V rails - one for the relays (bulk of the 700mA current) and one for the op-amps but it depends on the mix of currents and I can't realistically guess what that is.