After all that DIY advice I suggest look for decent shop and let them suggest a configuration.
Tell them clearly what you want like no gaming, video card with 3 outputs for linux, etc.
If you feel like it publish what they suggest here or in another forum. But it's likely that you will get "advice" how you should change that in 100 different ways...
I built PCs since forever. Like someone wrote above: It's not that difficult. But some people make id difficult by selecting some special RAM modules, etc. My advice: keep it simple and mainstream.
And last but not least: Get a quality power supply from a good brand. It doesn't need much power if you don't play games. But it should be high quality. In many PCs the cheap power supply is the biggest problem - and something which is often overlooked.
In Bangkok I order most of my parts from JIB. Good website, good advice, fast delivery. I don't know if you also deliver to CM. I guess a good local shop would be best, but if you don't find one then a good shop far away is better than a bad shop nearby.