I've used oak chips, cubes and more recently honeycomb pattern toasted wood (cherry wood)... All medium toast. I find that cubes are better than chips in that what they provide is more stable. With chips, expect it to change, drastically, over time (over the next few/several months) before settling into something close to what you get from cubes (but still not as good). Also with chips, it's more of a single note, where with cubes you have several notes to the contribution. I've not had a sample from the honeycomb pattern batch yet, so the jury is still out there.
I would advise researching what the different types of oak, and toast levels, will do for a brew before you start adding any. I would also not soak the wood in anything for the first few tries. IMO, if you're planning to add toasted wood/oak to a brew, do it to get the flavors from that wood.
Personally, I wouldn't want to add wine flavor to my beer by adding wine soaked wood to it. IMO, if you want that character/flavor in a beer, brew it up so that it will have it, or develop it on it's own.
I would also advise adding at least an ounce of the wood to the brew. Give it 4-6 weeks and then pull a flavor sample. If you don't think it's enough, add some more of the same wood to it, and give it another 4-6 weeks. The cubes I usually use claim full extraction in 6 weeks. I have a wee heavy with 3oz of medium toast Hungarian oak cubes in it. It's been sitting like that for almost 15 weeks now. I'll probably pull a taste sample the next time I'm brewing (in about 3-4 more weeks) to see where it's at. Since it's a 12% brew, I'm not worried about the oak being in there so long. I've already planned on not going to glass with it until fall (at the earliest).