It really depends on your budget more than anything else and to be honest, there is not one over another that would be right to recommend.
The best recommendation I can make it head down to a Calumet if you have one, if not Jacobs and Jessops will do. If you want something that you only need to buy once, be prepared to spend around £100-£150 or more if you wish and in theory, that should serve you for life.
Firstly the tripod itself. You can get tripods with heads all in one which can be a nice easy setup but the minute that head breaks or becomes loose, kiss that goodbye. Plus if you needs change, you are pretty much stuck.
When loking at tripods, you need to consider weight. It may not seem like a big deal at first but if you plan to do a lot of walking, you will want something lightweight. There are carbon fibre ones out there but due to the materials, not cheap. Some tripods have latch clips to secure the extended legs and others have screw type grips so once again, personal preference. Some tripods have a central peg which can be removed and then fitted in another direction.
Then the same with heads, there are so many different types. You have trigger grip, fluid heads, pan/tilt heads. Each can be utilised to work to your advantage but really you need to try them for youself.
The problem with photography as a whole is that everyones expectations and requirements are going to be difficult to say, "This is what you need". I would personally say, consider what you have and the value of your product and try not to look for the cheapest tripod which will just "do the job".
To be honest, virtually any tripod out there should have no problem holding the weight of your camera+lens. Just steer clear of those mini tripods etc.
