If you go shopping and you have a later model car with the immobilizer chip in the key, be sure to check to see if there is a suitable immobilizer module (some require that you permanently insert a key into the module) available for the car. The other option is to do the deep dive into the ECU and wire in a permanent by-pass of the immobilizer daughter board. If you have a pre immobilizer car then this is not an issue.
Personally, I am adverse to putting aftermarket electronics into anything that approaches mission critical status. Most of the retail level stuff has dodgy reliability and definitely no long term support. If you could somehow adapt a push to start system from one of the newer Honda / Acuras that might provide a more durable option. However, I expect that these systems are integrated into the PCM so retrofitting is not a realistic option.