I personally think it is a missed opportunity not to convert a HMO yourself. If you invest in the adequate research for the area, the market and the right property then with a good builder a conversion should not be too difficult. Essentially turning downstairs reception rooms into bedrooms and adding the right balance of en-suites or shared bathrooms for your target market.
Your profit margins will be significantly greater and your experience will grow through the process.
The right builder is a key ingredient so choose diligently and my advice is to lock down costs through a structured fixed price contract.
There is plenty of free advice on line and through networking events. Go for it!!