Regarding hosting providers, all our codes are tested on:

99.99% our clients use cpanel, this is best and most easier way to go

Everything else like custom servers just causing unpredictable unnecessary trouble for us and our clients, is very hard to support such clients.

Example php modules from our demo hosting:

bcmath,dom,fileinfo,gd,imap,tidy,xmlreader,xmlrpc,xmlwriter,xsl,zip,intl,json,mbstring,mcrypt,mysql,mysqli,opcache,pdo,pdo_mysql,phar,posix,soap,sockets

from php.ini this parameters are important:

* upload_max_filesize = 128M
* post_max_size = 128M
* max_execution_time = 5000
* max_input_time = 2000
* memory_limit = 512M
* max_input_nesting_level = 128
* max_input_vars = 10000
* output_buffering = 4096