Small flower: Chiisana Hana or Chiisai Hana?

I have to write a short story for a class assignment and I was thinking about writing one about a girl named little/small flower. And so since I know that 小 Chiisai means "small/little" and that 花 Hana means "flower" I thought it would be 小花 Chiisai Hana but when I asked other people and looked it up online I also saw this: 小さな花 Chiisana Hana. My question then is which one would be the correct one or at least the best one to use? Also if it's not too much trouble I was wondering if somebody could explain in an English manner, like first name first and last name second, which one would be considered which most commonly in Japan? Like would Hana be the first name and Chiisai/Chiisana be the last name, or would it be the other way around?

Neither 小さな nor　小さい　can be a person's name on the first place. 花 can be a first name, though it sounds like a 100 year old lady's.

Make her first name 小花, pronounced for example こはな, which is unusual but does not sound weird; and her last name whatever you want.

There is a manga artist named 小花美穂 (おばな　みほ).

But it is associated with 小鼻 (kohana, small nose), I'm sorry to say.

Fair enough, use another pronounciation then.

"Chiisai" is more about the physical size, and "chiisana" includes additional meaning of (small and) cute, if you are asking about the differences in nuances.

However, as noted already, while "Hana" can be a girl's first name, neither "chiisai hana" or "chiisana hana" can be a girl's first name at all. And it cannot be a full name (first and family names) for a person at all in Japanese.

小 can never be read as "chiisai" nor can it be read as "chiisana". It is read as "chii" (among other ways to read it) which doesn't make sense, by the way. If you want to write "chiisai" or "chiisana" using the Chinese character, you write it as 小さい and 小さな respectively. But then, it's not a name.

小花 (Kohana) is alright.

But it is associated with 小鼻 (kohana, small nose), I'm sorry to say.

Well then, the pretty and common name 花 (flower) also sounds the same as 鼻 (nose) too. That's not a problem. Besides 小鼻 (small nose) is a compliment, although these characters would be weird as a Japanese name.

the pretty and common name 花 (flower) also sounds the same as 鼻 (nose) too.
not the same: ha'na (花 or 華 as a name) and hana (鼻)
小鼻 may be a compliment but very funny for a name.

Well, yeah, and 小鼻 is supposed to be read as "kobana" and not "kohana" anyway.

In the idiom "kobana ga ugomeku" etc., it's kobana, but otherwise, it's read as "kohana" as well.

http://黒毛穴さん.seesaa.net/category/23356607-1.html
小鼻（こはな）の毛穴黒ずみを取る方法は何があるでしょうか

http://ejje.weblio.jp/content/%E5%B0%8F%E9%BC%BB
小鼻
日本人苗字
こはな Kohana
おばな Obana
こばな Kobana