I gather from your message that you're not yet sure if the problem is fuel or ignition related. Pull one of the plug wires, put one of your old plugs in it, ground it, and then crank the engine and see if it has spark right from the first revolution. If there is no spark, at least you know in which direction to start looking.

If there IS spark, but it is still slow to catch, it could be something like the fuel check valve is allowing the fuel to drain back when it is shut off. Or the Radio suppression relay may be going bad.

Is the problem worse after the car has been sitting for a few hours, or worse upon warm restarts, or equally bad either way?

Have you read-out the fault codes? (See 700/900 FAQ's)