A few things to watch out for, if your team doesn't have a lot of experience in direct management of dedicated servers/datacenters:
- There is an increased risk of larger/longer very rare outages due to crazy circumstances. Make sure you have a plan to deal with that. (I've had servers hosted at a datacenter that flooded in Hurricane Sandy, and another where an electrical explosion caused a >3 day outage..)
- It's easy to think you'll rely on managed services, but that rarely works out well. It also can become very, very expensive -- possibly more so than cloud-based hosting.
- Specifically, regarding H1, H2: Dedicated hardware is substantially cheaper than cloud-based hosting, but if you rely too much on managed services you negate a large portion of the savings. Consider that most service providers will be both more expensive and less competent than doing it yourselves. Also, having your own team have direct knowledge + their own documentation of the setup will be beneficial.
- I'd recommend budgeting for and ordering some extra parts to keep on hand for replacement, if you are having datacenter ops handle hardware or can have an engineer located relatively close to your datacenters. (A few power supplies, some memory, a couple drives - nothing too crazy.)
- Supermicro's twins systems are great. In the past I've gone with their 1U models vs. 2U to slightly reduce the impact of unit downtime. (Having to take one 2U Twin down affects four nodes. It sounds like you'll have to decide on balancing that against the increased drive capacity, in your case.)
In a long run, probably. Immediately after deploying, unless they hire very experienced, I expect quite a few "never seen before" issues (may not result in publicly visible downtime though). Monitoring for "thermal events", weird and hard to debug issues requiring firmware updates, "bad cable" issues, etc. are not what you have to deal with in the cloud.