He is confused as to whether he should marry a virgin or a widow

This
depends on the situation of the husband; it may be that marriage to
a widow is more suitable for him, and better. 

The
widow may be a lady of religious commitment and good character, such
that you would not want to let the opportunity to marry such a woman
“slip through your fingers”, and you could not find a virgin of such
religious commitment and character. 

But
generally speaking, the Prophet
(peace and blessings of Allaah be upon him) encouraged marriage to virgins. 

There
is the story of Jaabir (may Allaah be pleased with him), whose father
had died, leaving him with sisters. In his case it would not have been
suitable for him to marry a virgin who was young like them. So he wanted
to marry a woman who had been previously married, who could take care
of them and look after them, and the Prophet
(peace and blessings of Allaah be upon him) approved of his decision. 

It was narrated that Jaabir ibn ‘Abd-Allaah
(may Allaah be pleased with them both) said: “The Prophet
(peace and blessings of Allaah be upon him) asked me, ‘Have you got
married?’ I said, ‘Yes.’ He said, ‘A virgin or a previously-married
woman?’ I said, ‘A previously-married woman.’ He said, ‘Why not a young
girl, whom you could play with and she could play with you?’ I said,
‘I have sisters and I wanted to marry a woman who could gather them
together and comb their hair and take care of them.’ He said: ‘You will
reach, so when you have arrived (at home), I advise you to associate
with your wife (that you may have an intelligent son).’”

(Narrated
by al-Bukhaari, 1991; Muslim, 715) 

According
to another report narrated by al-Bukhaari (2257), “… so she could teach
them and discipline them.” 

According
to another report narrated by al-Bukhaari (2805) and Muslim (715): “He
said: ‘The Messenger of Allaah
(peace and blessings of Allaah be upon him) said to me, when I asked
his permission (to participate in jihaad), “Have you married
a virgin or a previously-married woman?” I said, “A previously-married
woman.” He said, “Why did you not marry a virgin whom you could play
with and she could play with you?” I said, “O Messenger of Allaah, my
father has died (or has become a shaheed/martyr), and I have
young sisters, so I did not want to marry someone like them who could
not discipline them or take care of them, so I married a previously-married
woman who could take care of them and discipline them.”’” 

It was narrated that Jaabir (may Allaah be
pleased with him) said: “My father died, leaving seven – or nine – daughters,
and I married a previously-married woman. The Messenger of Allaah
(peace and blessings of Allaah be upon him) asked, ‘Did you get married,
O Jaabir?’ I said, ‘Yes.’ He said, ‘A virgin or a previously-married
woman?’ I said, ‘A previously-married woman.’ He said, ‘Why not a young
girl whom you could play with and she could play with you, and you could
laugh with her and she could laugh with you?’ I told him that ‘Abd-Allaah
had died and left behind daughters, and I did not want to bring to them
someone like them. So I had married a woman who could take care of them
and discipline them. He said, ‘May Allaah bless you,’ or similar kind
words.”(Narrated by al-Bukhaari, 5052) 

Shaykh
Mustafa al-Ruhaybaani said:

“It is
Sunnah for the one who wants to get married to marry a virgin, because
the Prophet (peace and blessings
of Allaah be upon him) said to Jaabir, ‘Why not a virgin whom you could
play with and she could play with you?’ (agreed upon) – unless there
is a reason for which marrying a previously-married woman is better,
in which case he should choose such a woman over a virgin, in order
to serve that interest.”(Mataalib Uli al-Nuha, 5/9, 10) 

And Allaah
knows best.