I used SPDs on my commute, For me they give the correct mix of srcure in the bike, easy unclip and walking from bike-stand to the office is a doddle.
I would definitely try them on the turbo and get used to unclipping. I started on the old M737 pedal a long time ago so clipping out sideways is now a reflex and after a couple of months on the turbo befriended the road bike arrives yoinwil develop the reflex. however, you may want to see if the cleats that offer unclipping in any direction suit yup better, I think these are the silver ones, other can give you advice .
In terms of comfortable pedals and choice of shoes, I have never had problems for rides under three hours and issues thereafter have been about cleat position, this toy will need to experiment with. There are also SPD models that offer greater platform size, A520 and A530, i have some 530s on my touring bike and like the flexibility of single Sided SPD . It does mean you need to find the right side to clip into, but I grew up on clips and straps so flicking the pedal with your toe to bring on correct side up is not a hardship for me.
One last point, on the commute I will always err on 5he side of caution and unclip early when approaching a red light and or filtering: avoiding someone stepping out between cars or being doored is much asker with one foot free!
