New to vps I have a few questions

Performance-wise there is not a major difference between the available distributions. I would recommend choosing either CentOS or Ubuntu. We offer the largest variety of tutorials for Ubuntu.

We do have a tutorial for ajenti here. While it is targeted at Ubuntu 13.04 it should be possible to use these instructions to get it up and running on 14.04.

“which distro is the most stable / fastest I was going to try Centos”

All the droplet OS installed on Digital Ocean are from stable release channels. Picking which Linux to use is more a personal choice, but if you want to maximize resources on a small node some distros have a lighter footprint than others.

I use Ubuntu because I can find install packages for it for most stuff I want.

“if I select LAMP under applications during the creation of my droplet does that install all the web services - so no need to manually install them”

Yes, the LAMP option for droplets comes pre-installed with what you would get if you ran apt-get install lamp-server^. It does look like DO has made a few tweaks to finish the install for you. So all you have to do is set the root password for MySQL.

Take a look at the other developer stacks available as well. There is the LEMP and MEAN stacks.

“I develop websites and play around with web scripts and I thought this would be a great way to pick up some linux skills”

Create a droplet, play with it, destroy it and repeat. I’ve tried a bunch of the pre-configured applications. Some of the ones I recommend try are GitLab,Docker and the node-v0.12.2.