Shin Kanzen Master books are usually recommended. There are separate books for vocab, reading, grammar, listening. Maybe there's even one for kanji. There are scans available online, so you can just google for them. They're called 新完全マスター in jp, and use 語彙 for vocab, 文法 for grammar, 読解 for reading, 聴解 for listening, and I'm sure you know how to spell kanji.
Although I bought mine from Amazon.
That being said, I don't think the vocab books are of any use, there are plenty of vocab lists on the internet for any SRS app you might want to use. There are also lists of grammar points, so I wouldn't use a book for that either. Besides, in my experience, all those grammar points, from the internet or from books, did not come in handy at all. Whatever points there were in the references did not appear on the test. Moreover, the fill in the blank grammar questions were more complex than one or two words, I think you had to insert practically a whole clause. Basically, I ended up relying on my inner sense of Japanese, which was clearly not up to the task, but luckily, the grading is very lenient and curved. I.e. rather than be good at Japanese, you just need to be better than the other losers.
Similarly, I don't believe studying kanji will be very useful. Kanji questions on the test are based on vocab. E.g. you are given a word in context spelled out phonetically, and you must provide the correct kanji spelling. Or you are given a word spelled in kanji, and you must provide the correct reading. Therefore, your success comes not just from pointlessly memorizing kanji, but from memorizing actual words from the vocab lists and the kanji used to spell them.
Naturally, all vocab and kanji lists include words from past tests, but you'd better believe they try to insert words not on those lists into new tests. I remember how I got a nice wake up call on the very first question of my test when they wanted to me to give the reading for 厳正, and that word hadn't been on any vocab lists I had studied (or in any books, for that matter). I was like "I'm 90% sure it's gensei, but it could possibly be genshou too...", and of course the test had both options. Agonizing about the answer to the first question is a serious psychological blow for the rest of the test, to the point I still remember it. Just be prepared for it.
Now, what I would concentrate on if I were you is reading. Get the dokkai book by all means. You must get used to those questions. Not only get used to them, but learn to read FAST. Reading is the biggest section and it takes the most time. You must be a fast reader to do well overall. I only took the N1 test, and I'm sure N2 reading is quite a bit easier, but I remember this is the part that seriously kicked my ass. I had been scared of choukai the most, but after the reading section, I felt like listening was a time for me to relax. I swear I drank like two bottles of water during the break after reading. But do get the choukai book as well. Those would be the only two books I'd find useful for studying. The rest is SRSing vocab and grammar points. We're very lucky there is no writing on the test.
Oh, and a final note... If you have a whole year left, you should go for N1. Yes, it is difficult, but, like I said, the grading is very lenient, and a pass is still a pass, even if by a small margin.