Hi there, can do it, i did similar stuff in the past to send quotes, trades, indicators and other info to mt4 to a mysql database that then can be read with php for example and display in a website.
Can do it for other platforms as well, i know is possible in ninja trader, probably is possible in calgo and most probably all platforms will have a way to do it.
we can get started in mt4 as it is the easiest for sure, your clients will have to load an EA with a unique username/password we will send to them in order to write his data to his "web account".
then , in a web site they can log in and see their trades or you can have a backend where you see all your client usernames, click into one of them to see their trades, etc. whatever you need, once we have the data in the database is possible(balance charts, global stats like what asset your client trade more, etc).
if interested pls contact me and we can talk further.