The most common and most likely answer to this crossword clue is the 2 plus 4 plus 6 letter word UP ONES STREET
I've seen this crossword clue in Financial Times
U
P
O
N
E
S
S
T
R
E
E
T
Buddy explains!
The straight part
We know that "Perfectly suitable" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case perfectly suitable = up ones street.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.