I'm at the limit of my knowledge here, so all I am doing is reading the Companies Ordinance (which I assume you can do also). I see no distinction in most places between companies limited by guarantee and those limited by shares and those with unlimited liability. They all need only one director, but there must be a separate Company Secretary (which can be a body corporate). I see little difference in the paperwork - they all require a Memorandum of Association and essentially the same filings. Those limited by guarantee seem to require more in that they require the guarantees of the members. "Company" is a generic term. Each company must be of one of the three types I listed previously: limited by shares, limited by guarantee, or unlimited.
For company setup (which generally means taking an off the shelf company and changing its name and the particulars of the director(s) etc) then a one-time fee of $2500 is in line with my expectation (but I have no experience of doing this in Hong Kong, only in the UK). For acting as company secretary, and dealing with all the regular filings and so on (but not necessarily including the the accounts) I have seen people quote figures in the range HK$5-10,000 per year. That might include the accounts if they are very straightforward.
Again, I haven't done this. I am simply reading the Companies Ordinance and relaying what I have heard other people report.