I get your reasoning on not wanting to change accounting systems multiple times. But let me say, choose what will work for now, and say the next ~12-18 months (longer is great, but I wouldn't try to predict it). Don't try to look beyond that because you are just wasting cycles on something that will likely need to change even if you think you know what you will need for the next 5 years.
I see 10-20M a year businesses still on Quickbooks and doing ok with it, although most have some custom reporting or solutions added on for things like shipping, manufacturing etc. But moving to a NetSuite, Oracle, SAP etc type product is a lot for a startup to manage. You are looking at a minimum of a 3-6 month implementation for one of those enterprise level systems in which time you might change things considerably and spending the $50-100k+ on that is likely not the best use of funds early on.
I could be totally wrong as every situation is different, but I'd either stay with QB as long as possible or pick something reasonably simple that does not require implementation consultants to spend 2-4 months evaluating, configuring and making things work. Now if you are into your Series A or have real revenue and a CFO etc, then my advice would likely be different.
As for options, depending on what you need, Xero, Quickbooks, NetSuite, SAP, Sage (Sage 100) etc. I'd outsource payroll to ADP or someone similar (PayChex etc), simply because it makes life far easier and the cost is fairly minimal.
