The lock I am having trouble with is a Lockwood 110/30 brass padlock:



Firstly the main problem when I am SPP it is I will reach a point where no other pins seem to be binding, or that a tall pin near the very back is binding. The problem being that I lose most of the feeling in my pick the further back in the lock I get. Another problem I have is that when I am picking it and I reach towards the back of the lock it feels as though I am running into something. I think it is a tall pin that is binding, as when I release tension and push my pick forward I can move it further back. I think that the type of pick I am using has just too sharp a curve to be able to get over this pin. I am expecting some new picks soon, including one with a shallower hook so that might fix it. I am unsure if there are any security pins in it and have had no experience in picking them.
I have picked it twice already, though mainly from luck i think. The first time I was using a s-rake and got it when i wasn't really paying attention, all of a sudden it popped. The second time I was attempting to single pin pick it and I think I bumped some pins with the shaft of my pick and it sprang open. I am quite new to picking, I only started a couple of weeks ago. I have picked both my front and back door lock several times each and a small Master padlock. All of these were quite easy, especially the Master. I know Lockwood may be a bit too difficult for a beginner to start with so if you have any recommendations feel free. (I live in Australia)
I have also been looking at a re-pinnable practice lock. I want to get one of these so I can get used to security pins and to just get a better feel for picking. This is the lock I have been looking at:
https://learnlockpicking.com/product/6-pin-ultimate-challenge-practice-lock/
I also looked at MrWizards lock as it has been mentioned on this site but as far as I know he doesn't ship to Australia. Please let me know if you think this is a good lock, I am on a pretty tight budget, with shipping and currency differences it comes to a pretty expensive buy so I just want to make the right choice.
If it helps these are my picks:

Thank you to anyone who replies, I hope you guys can help with my lock.