Why don't you focus on the problem rather than adding more complexity?

Your problem is slow recovery on restart. If you're not careful, adding HA could make things worse. Do some investigation, figure out why you're getting slow recovery, whether it was a once off or whether it's a consistent problem

If you insist on implementing HA, then start by identifying SLAs. You've said 2 hour downtime is acceptable. Do the business users agree? What about data loss allowance? What's the unit of failover? If the DB fails over to the secondary server, will the app work? Are there other resources the app needs that also have to fail over? Do you have the hardware for the planned HA/DR strategy? If not, what's the budget to buy more? Do you have the skills to manage it? If not, what happens when something goes wrong?

HA/DR planning is a hell of a lot more than just 'what singular technology are we going to use'.