I don't have full use of my left leg below the knee following a number of unrelated accidents over the years, the worst leaving me slightly 'paralysed' (more of a weakness with some loss of sensation) down the entire left side of my body. then a dog rearranged part of my lower left leg 11 months ago tearing out a major nerve which as left me unable to balance on my left foot (can't feel much either and have little control of the limb below the knee). Finally adding hypermobility syndrome to the situation leaves me needing high ankle boots for all footwear, so SPD's are out - none of them are high enough ankle to give me the support I need and I also need extra depth in the boot to be able to take a custom orthopaedic inner sole.
I use standard pedals on all my bikes (
http://www.wiggle.co.uk/mks-mt-lite-pedals/) fitted with toe clips & straps. (
http://www.sjscycles.co.uk/nylon-toe-straps-black-prod825/) I cycle in high ankle soft leather hiking boots all the time with no issues including on my road bike - basically I need the boot to hold my ankle in position for me and the pedal to hold my foot in place. The pedals I use really grip my boots well and hold my foot where i need it held and can't hold it there myself - the toe clips & straps stop it sliding round to odd angles which works well for me, but allows for the sideways position the foot tends to adopt.
Toe clips take a touch of pratice, no different to SPD's and can be used on any bike, so go and get the bike you want and then fit the pedals you need to it.