
Hi Duke!
I'm going to be very honest here - I would not get another dog yet. From your other post about control outside the house, it sounds like you have a lot of work to do with your current boy - adding a dog will only increase your workload. Even if it didn't pull, lurcher X still would - and take it from me, it is not possible to train a dog not to pull (excepting the use of headcolalrs or no-pull harnesses) whilst trying to walk one that doesn't - leash pops don't tend to work, so every time you correct the puller by stopping or going back, whatever your method, you find yourself correcting the other dog for walking well. Then you find yourself doing twice the walks to train the puller by himself - not fun, i've had to do that a lot with my two - my dobe pulls, my rott X doesn't. The same is true of your guy criss-crossing in front of you and changing sides - correcting him for that will only frustrate another dog by disrupting its otherwise pleasant walk.
You msut also consider that another rescue dog may well carry its own set of problems - small animal aggression, dog aggression (i know it sounds odd to have a dog-aggressive dog living with a dog, but my bro's dog is like this - gets on fine with mine tho!), or other problems - that could make walks even less fun than they are! Or, it could teach your exuberant lad other bad habits, or he could teach the new dog bad habits.
I don't mean to be horrendously pessimistic - i'm aware it's kind of coming across that way! Of course there is a chance a new dog would work out fine. But I would recommend working with the dog you have - placing him in some training classes would be a good start - before you get another one and double your workload. My two are fairly well behaved (so I'm told, anyway..) and I find they are an awful lot of work. They both have bad recalls like yours - and having to train good recalls in two dogs as I'm having to, as thoroughly as is necessary, is like a full time job. Incidentally, here's the method i'm using:
http://www.shirleychong.com/keepers/Lesson6.html
For the pulling, I have been clicker training my dobe - you don't need a clicker if you're not familiar with them, though. I would treat your pup for walking where you want him to, and say "heel" or whatever your command is. Treat him a lot to start with until he's fairly reliable and responsive, then start gradually treating him less - if he starts to lapse, up the treats and then fade them more slowly. It can take quite a while, but it seems to be quite effective. Another method is to stop and walk backwards 6 steps every time he pulls - also quite effective. With both methods, or any you decide on, you msut remember to _never_ let him pull, not once - or he will elarn he can get away with it occasionally. Strangely enough, occasional reinforcement often makes the behaviour stronger than regular reinforcement - it's the same mental process that gets people hooked on gambling. Above all else you do, remember to stay calm and consistent - pick a method and stick with it, and no physical corrections (apart from guiding him back to where he needs to be, of course) or shouting - i've noticed in my own dogs that when your volume goes up, they tune you out.
Good luck, I hope all goes well for you!