It'd probably be best to ask John to take a look at your pictures and for him to answer the question of whether a stock unit would work for you or not.

Taking a look through your pictures again, it's hard to see exactly what level of curl your hair has since it's so short in most of the pictures. In the picture where it's longer, to my eye it looks like maybe a light wave at most, or at least a style you could easily achieve with some product and the body wave that comes on the stock unit though.

If you want an precise match to your own hair's natural wave you'll probably need to grow it out a bit longer (4-5cm) and send in a sample to get a close match. Hair needs to be about that length in order to judge the amount of curl accurately. Anything else would just be a guess.

Do you want to try to start off trying to replace your hair as short as it is now and progress through several slightly longer units until you reach the length shown in your older photo, or will you let your hair grow out some before installing the first piece?

The reason I'm asking is, as several people have stated it's going to be very hard to cut a hairpiece down to as short as yours is now and get a decent blend.

Normally, units come with 6" of hair that you then cut down to whatever length you want it after it's bonded. My thinking from what you wrote in your first post was that you'd probably grow your hair out some, then have the unit cut-in to look similar to the picture where your hair was longer. You said you wanted to wear it spiked up.

Perhaps I was mistaken. Sorry about that if that's the case, but at least you've gained a lot of input and gathered several good ideas about possible hairline shapes and coverage areas from this thread as it stands so far.

Now would probably be a good point in time to call John to discuss your options in greater detail directly over the phone to narrow everything down a bit. He'll definitely be able to answer questions and guide you through the correct steps to make your first order as successful as possible.