Notebook Safe In Samui/lamai (and Accomodation)

Dear forum members,

I'm planning to stay one month in the beautiful LOS, my staying will be a mix of work (15days) and vacation (15days), so I'm thinking about booking something like an apartment or residence-like room with wi-fi Internet in Lamai for a whole month or a bit less and to bring with me my notebook to make some working activities onsite there (let's say to check email sometimes and to check things for future longer staying ...).

In the last two weeks (the vacation period) a friend of mine will arrive and the main idea is to roam a bit around (Koh Tao, Ang thong, Phangan, etc.) maybe spending some night outside Samui but keeping the "basement" in Samui/Lamai for the heavy luggage. So I'm wondering if a safe deposit service for notebook

exists, to leave without worries the work stuffs during the vacation days (something like Mail boxes etc. or similar, or maybe some hotel can provide this service alone without the need of booking the room, or some bank...)

Does someone know or use something like that?

BTW: I also kindly accept suggestions about the accomodation in Lamai, if you are an owner, or you know someone whom his, we could fulfill each others requirements The period is around 24 february to 24 march, but to be defined better as maybe I'll stay some days in BKK, arriving in Samui some days after.

Thanks in advance and kind regards

Fabio