Hi Pravit. You are in the right place to discuss this. I also saw your post on one of the local Buffalo facebook forums, and will caution you that you are going to get a WIDE variety of feedback from a WIDE variety of investors -- especially on that group!
I suggest you "dial in" what you are asking. You are casting a very wide net without providing what your prioritized criteria might be. Are you looking for cash flow? Appreciation? Ease of management? Tolerance for value-add? Speed of building a portfolio (Cash-on-Cash return is a factor here)? I think your questions are a bit to general and you are going to get even more general responses. However, I'll take a stab here.
What town should be easier to manage? This completely depends on what you are looking for. Cheap houses in lower class neighborhoods will get you cash flow with a lot of headache. Class A properties are going to cost you more, have lower cash flow, yet be more attractive to a higher quality tenant base. They generally will offer greater appreciation, as well.
Management. I also self-manage my portfolio, but I also live here and have the time/knowledge/resources to do so. Property management can be great if you are willing to give up a percentage of your gross rents to not deal with headaches, but it's not like you can just ignore your asset. You will still have to make decisions, and ultimately, you are entrusting someone else with your asset. It works great for many people -- not me -- but it might be your best option considering your distance.
If you are going to self-manage, you need a great TEAM. You need at least one handyman on speed dial (preferably more), a good contractor for the bigger things, roofer, plumber, electrician, cleaner, etc etc. Preferably 3 deep in each of those categories. Of course, you don't need to do that before investing, but you need to be building that list. You also need a leasing agent, unless you are going to advertise and screen tenants yourself. In this case, get familiar with NYS landlord/tenant law or find someone who is.
You mentioned the UB neighborhoods. Keep in mind that this comes with high turnover, and (often) students who will beat the hell out of the property! Not all of them, but eventually, they will! This could be very difficult if you are going to self-manage, as you will be turning units every year and dealing with a lot of repairs. My business partner does a lot of work for UB property owners and shares some pretty rough stories with me. It's just not a subclass I want to be involved in, but perhaps you can make it work for you!
My closing advice is that you connect with a local agent or mentor who also invests in the neighborhoods you are considering. Be wary of the facebook groups as most folks will have a "pitch" or just see the possibility of a transaction. Find someone who can help you dial down on what YOU want as an asset, and has experience with that kind of property. Buffalo changes very quickly block to block (not just ZIP by ZIP) and it is crucial that you understand this prior to writing any checks. The same street with the difference of a hundred house numbers can look drastically different.
I hope this helps, rather than be discouraging. I would spend time building your list of WHO (agent, mentor, contractor/handyman), then WHAT (house type, tenant base, work needed), then WHERE (location). Happy to connect via messages if you'd like to dive deeper.
Tim