Installing Horde 2.0 on Red hat 7.2 - Wrong PHP / PEAR Versions

[Computers in Medicine]

I would like to install Horde 2.0 under Red Hat Linux 7.2. I read that one
of the requirements was either PHP 4.0.6 with a manually upgraded PEAR or
PHP 4.1.0. RH 7.2 comes with PHP 4.0.6 so I tried just upgrading PEAR
through the following steps:

1. Download pear-4.1.0.tar.gz from www.horde.org/pear

2. I unpacked it and found it contained the following contents

Archive/    Cache.php   DB/         HTTP/     Log.php   Net/
PEAR.php    Benchmark/  Console/    DB.php    HTTP.php  Mail/
Numbers/    Schedule/   build/      Crypt/    File/     Image/
Mail.php    Payment/    System.php  Cache/    Date/     HTML/
Log/        Math/       PEAR/       XML/

3. At www.horde.org/pear I found following instructions:
To install this package simply backup your current /usr/local/lib/php (or
wherever PEAR lives on your system; /usr/local/share/php/pear is another
possibility) directory, and uncompress the contents of the archive above
into that same directory.

4. /usr/local/lib/php contained exactly the same files at the archive I
downloaded, with the exception of one more directory called extensions.

5. I thought I was all set, I backed up the contents of /usr/local/lib/php
and copied the files from the pear-4.1.0 archive into /usr/local/lib/php. I
also copied the extensions directory that had been there.

6. I tried http://my.host/horde/test.php and it told me I needed a more
recent version of PHP. Also, here's the phpinfo():

'./configure' 'i386-redhat-linux' '--prefix=/usr' '--exec-prefix=/usr'
'--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc'
'--datadir=/usr/share' '--includedir=/usr/include' '--libdir=/usr/lib'
'--libexecdir=/usr/libexec' '--localstatedir=/var'
'--sharedstatedir=/usr/com' '--mandir=/usr/share/man'
'--infodir=/usr/share/info' '--prefix=/usr' '--with-config-file-path=/etc'
'--disable-debug' '--enable-pic' '--disable-rpath'
'--enable-inline-optimization' '--with-apxs=/usr/sbin/apxs' '--with-bz2'
'--with-curl' '--with-db3' '--with-dom' '--with-exec-dir=/usr/bin'
'--with-gd' '--with-gdbm' '--with-gettext' '--with-jpeg-dir=/usr'
'--with-mm' '--with-openssl' '--with-png' '--with-regex=system' '--with-ttf'
'--with-zlib' '--with-layout=GNU' '--enable-debugger' '--enable-ftp'
'--enable-magic-quotes' '--enable-safe-mode' '--enable-sockets'
'--enable-sysvsem' '--enable-sysvshm' '--enable-track-vars' '--enable-yp'
'--enable-wddx' '--without-mysql' '--without-unixODBC' '--without-oracle'
'--without-oci8' '--with-pspell' '--with-xml'

7. I don't know why the updated PEAR wasn't being recognized. Maybe it's
obvious, but I'm a PHP newbie. I decided to try upgrading PHP istelf using
these RPMs which I got from here:

http://www.aucs.org/rpmcenter/rpms.html

php-4.1.1-1.i386.rpm
php-devel-4.1.1-1.i386.rpm
php-imap-4.1.1-1.i386.rpm
php-ldap-4.1.1-1.i386.rpm
php-manual-4.1.1-1.i386.rpm
php-mysql-4.1.1-1.i386.rpm
php-odbc-4.1.1-1.i386.rpm
php-pgsql-4.1.1-1.i386.rpm

I got back
error: failed dependencies:
curl >= 7.9.2 is needed by php-4.1.1-1
libcurl.so.2 is needed by php-4.1.1-1
libpng.so.3 is needed by php-4.1.1-1

So I tried adding

curl-7.9.2-1.i386.rpm
curl-devel-7.9.2-1.i386.rpm

and still got

error: failed dependencies:
libpng.so.3 is needed by php-4.1.1-1

So I tried adding

libpng-1.2.0-1.i386.rpm

And got many errors saying that libpng.so.2 was needed by dozens of other
other packages.

8. In addition, horde/test.php tells me that I'm missing MCAL and Mcrypt
support in my PHP modules. The doc/INSTALL from Horde says Mcrypt is needed
to avoid using weak crypto and I don't know about MCAL but Horde must be
looking for it for some reason.

So, my questions are would it be better / easier to just upgrade PEAR or
upgrade PHP, and in either case can anyone suggest a way around the problems
I encountered. Also, can anyone tell me how to obtain MCAL and Mcrypt
support for PHP? Thanks in advance to anyone who can help!!