Who have used both? Which do you recommend?
has suricata a web interface?
Depends on what your priorities are. Suricata has some features like File Extraction that from what last seen are yet to be implemented by Snort.
I would say that although Snort continues to be a more mature product and with a larger userbase both are ready for production. To make your choice easier, groups like EmergingThreats continue to support both IDSs.
Suricata also can be managed with OinkMaster and also integrated into web based log analysis like Snorby or Sguil (limited functionality).
Snort is multi-threaded so if you are going to be processing a lot of traffic, this may be your bigger selling point.
However, if you are new to this, consider starting with SNORT as it is older and more documented.